monster

\ \ [13] Monster originated as a word for a ‘divine omen or warning’. It goes back via Old French monstre to Latin mōnstrum, a derivative of the verb monēre ‘warn’. From its original sense ‘warning of misfortune, evil omen’, mōnstrum was transferred to the sort of thing that could function as such an omen – a ‘prodigy’, or a ‘misshapen or horrifying creature’ – whence the meaning of English monster. The word’s connotations of ‘largeness’ seem to be rather more recent, first emerging in English in the 16th century.

\ \ Other English derivatives of mōnstrum, some of them reflecting a later sense of monēre, ‘show, inform’, rather than the original ‘warn’, include demonstrate [16], monstrance [16], muster [13] (which originally meant ‘display’), and remonstrate [16]. And from monēre itself come admonish, monitor [16], monument [13], premonition [16], and summon [13].

\ \ Cf.⇒ ADMONISH, DEMONSTRATE, MONITOR, MONUMENT, MUSTER, PREMONITION, REMONSTRATE, SUMMON